Olsen Irene E, Richardson Douglas K, Schmid Christopher H, Ausman Lynne M, Dwyer Johanna T
Departments of Nutrition, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.
Pediatrics. 2002 Dec;110(6):1125-32. doi: 10.1542/peds.110.6.1125.
To explain differences in weight growth velocity of extremely premature infants among 6 level III neonatal intensive care units (NICUs).
In 6 NICUs, we studied 564 infants, stratified by gestational age (GA), who were first admissions, survivors, <30 weeks' GA at birth, and in the NICU at least 16 days. Case mix (eg, birth weight, GA, race, illness severity, prenatal steroids), exposure to medical practices/complications (eg, respiratory support, postnatal steroids, necrotizing enterocolitis, infection), and nutritional intake (kcal/kg/d and protein in g/kg/d) were collected and used to predict weight growth velocity between day 3 and day 28 (or discharge, if transferred early) in multiple linear regression models.
Weight growth velocities varied significantly among the 6 NICUs. Adjustment for case mix and medical factors explained little of this variability, but additional control for calorie and especially protein intake accounted for much of the intersite variability. For the average infant, adjusted growth velocity ranged from 10.4 to 14.3 g/kg/d among the sites studied. The final predictive model, including case mix and medical and nutritional factors, explained 53% of the overall variance in growth velocity. Prolonged (> or =15 days) exposure to postnatal steroids and greater severity of illness both decreased growth velocity. The model predicted that adding 1 g/kg/d protein to the mean intake for our sample would increase growth by 4.1 g/kg/d.
Variation in nutrition explained much of the difference in growth among the NICUs studied. Mean intake of calories and protein failed to meet recommended levels, and the average growth in only 1 NICU approximated intrauterine growth standards. Increasing nutritional intake into the recommended ranges, in particular of protein, may increase growth of extremely premature infants up to or above intrauterine rates.
解释6家三级新生儿重症监护病房（NICU）中极早产儿体重增长速度的差异。
在6家NICU中，我们研究了564例首次入院、存活、出生时胎龄（GA）<30周且在NICU至少住院16天的婴儿，并按胎龄进行分层。收集病例组合（如出生体重、胎龄、种族、疾病严重程度、产前使用类固醇）、医疗操作/并发症暴露情况（如呼吸支持、产后使用类固醇、坏死性小肠结肠炎、感染）以及营养摄入量（千卡/千克/天和克/千克/天的蛋白质），并用于在多元线性回归模型中预测第3天至第28天（或若提前转出则为出院时）的体重增长速度。
6家NICU之间的体重增长速度差异显著。对病例组合和医疗因素进行调整后，只能解释这种变异性的一小部分，但进一步控制热量尤其是蛋白质摄入量则能解释大部分的机构间变异性。在所研究的机构中，对于平均水平的婴儿，调整后的生长速度范围为10.4至14.3克/千克/天。最终的预测模型，包括病例组合、医疗和营养因素，解释了生长速度总体方差的53%。产后长期（≥15天）使用类固醇以及疾病严重程度增加均会降低生长速度。该模型预测，在我们样本的平均摄入量基础上每天增加1克/千克的蛋白质，生长速度将提高4.1克/千克/天。
营养差异解释了所研究的NICU之间生长差异的大部分原因。热量和蛋白质的平均摄入量未达到推荐水平，只有1家NICU的平均生长速度接近宫内生长标准。将营养摄入量提高到推荐范围，尤其是蛋白质摄入量，可能会使极早产儿的生长速度提高到或超过宫内生长速度。
